Proceedings of the Ninth Mountain Lion Workshop - Carnivore ...

parcels) and non-preferred habitat (≤20-acre (8.1-ha) parcels). Patterns of habitat
avoidance and preference by parcel size were similar for all developed-zone pumas
sampled, with each animal using the 20 + -to 40-acre size class in a neutral manner. Yet
these mid-sized parcels also presented heightened mortality risks from human-caused
sources such as vehicle collisions or removal following depredation on pets and
livestock. Orlando et al. (2008a) found depredations, the primary cause of puma death in
our study, to occur on a mean property parcel size of 48.7 acres (18.9 ha), and median
parcel size of 18.0 acres (7.3 ha) in the Western Sierra study area. All pumas preferred
≥40-acre parcels more strongly during the day, and avoided ≤20-acre parcels more
strongly during the day. Pumas may have been avoiding use of human-dominated
environments during times of high human activity, but still relying partly on these areas
for hunting.
Management Implications
Rural development created preferred and non-preferred/high-risk habitat patches at the
individual level (third-order selection (Aebischer et al. 1993); disrupted functional
connectivity at the landscape level; and created a source-sink or source-pseudo-sink
condition at the population level for pumas. Source-sink population structures are not
necessarily unsustainable or uncommon among wide-ranging large carnivores (Howe et
al. 1991, Dias 1999, Noss et al. 1996, Pulliam 1988). Howe et al. (1991) found that a
large but finite proportion of a metapopulation can exist in non-sustaining
subpopulations, and these demographic sinks may connect source populations, aiding
overall viability. In a source-sink or -pseudo-sink condition, protection of large
demographic source areas, interconnectedness between sources, and protection of buffer
areas supporting sink populations is vital to maintain long-term viability (Hansson 1991,
Howe et al. 1991, Roberts 1998). The status of population subunits must be carefully
monitored. Thus, conservation of the study population mandates concern regarding
housing and highway expansion as a threat to source-area connectivity, and residential
development as a threat to puma habitat utility in buffer and source areas.
Most undeveloped foothill land in our study region is already slated for residential
development in parcel sizes of 40 acres or less (Strahlberg and Williams 2002, Stoms
2004, Walker et al. 2003). Although the higher elevation undeveloped zone of the
Western Sierra may continue to support pumas, this zone spanned only about 1.4 times
the average home range width of an adult male puma in our study population (Orlando et
al. 2008b). We expect further foothill development to constrict remaining source areas,
threaten connectivity, degrade marginal area habitats for pumas, and result in an overall
decline in numbers of pumas.
To conserve pumas and associated biodiversity, source areas, in our case the undeveloped
national forests and timberlands of the Western Sierra, should be managed for low or no
puma harvest, light exploitation of ungulate populations, minimum potential for livestock
conflict, and few opportunities for human-puma conflict (Cougar Management
Guidelines 2005). Rural developed areas in puma habitat should be managed as buffer
zones for source areas. State and county planning should aim to limit habitat
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